comedi_isadma_alloc(9)

✨ comedi_isadma_alloc — it's giving "set up my ISA DMA era" ✨

okay so bestie, this is a page from the Kernel API Manual, and it's about one very specific little function: comedi_isadma_alloc. She's the one who gets your ISA DMA all allocated and initialized in one go, no cap 🎀

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🌸 SYNOPSIS 🌸

struct comedi_isadma * comedi_isadma_alloc (struct comedi_device *dev ,
int n_desc , unsigned int dma_chan1 , unsigned int dma_chan2 , unsigned
int maxsize , char dma_dir );

like… six whole arguments, she's high-maintenance but worth it 💅

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💖 ARGUMENTS 💖

• dev — the comedi_device struct, aka the main character of this whole situation 🫶
• n_desc — how many cookies you want to allocate (yes, "cookies", that's literally the term, iykyk 🍓)
• dma_chan1 — the DMA channel for the first cookie ✨
• dma_chan2 — the DMA channel for the second cookie ✨✨
• maxsize — the size of the buffer to allocate for each cookie, like a lil snack size for every one of them 💜
• dma_dir — the DMA direction. which way are we going bestie 🌈

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🦋 DESCRIPTION 🦋

so what does she actually do? she returns the allocated and initialized ISA DMA… or NULL if anything fails 😭 literally anything. one thing goes wrong and you get NULL. no notes, that's just the vibe check result 💀

fr fr, always check for NULL — she will not warn you, she'll just hand you nothing and dip 🙈

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👑 SEE ALSO 👑

• Kernel file ./drivers/comedi/drivers/comedi_isadma.c — go read the source, it's the blueprint bestie 📖
• comedi_isadma_program(9)
• comedi_isadma_disable(9)
• comedi_isadma_disable_on_sample(9)
• comedi_isadma_poll(9)
• comedi_isadma_set_mode(9)
• comedi_isadma_free(9) — the one you call when you're done, don't forget her 🔥

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that's the whole page bestie, she ate and left no crumbs 💅

signed, sealed, delivered from ./drivers/comedi/drivers, dated October 2026, living under the comedi_isadma_alloc(9) header, in the Kernel API Manual — periodt 🧚‍♀️